OSI model & TCP/IP -- layering Flashcards
what does the OSI model stand for?
Open Systems Interconnection
The OSI model is a conceptual framework that describes _____ or ______ systems as seven layers, each with its own function.
networking, telecommunication
how do the layers help?
they help network professionals visualize what’s going on within their networks and how to narrow down problems
what are the 7 layers in order?
physical, data link, network, transport, session, presentation, application
the ____ layer is the one that most users interact with. it provides network services to the end user. it receives information directly from users and displays incoming data to the user. Web browsers reside here.
application
the _____ layer converts data from one format to another. it “presents” data for the application or the network. this information is sent to the session layer EX) encryption & decryption of data
presentation
the ____ layer creates a session so that two computers on different networks can talk to each other. this data is passed to or from the transport layer
session
the ____ layer is responsible for the transmission of data across network connections. EX) TCP & UDP
transport
the ____ layer takes care of packet forwarding, including routing through different routers. it handles the routing of the data, sending it to the correct destination EX) TCP/IP
network
the ____ ____ layer provides node-to-node data transfer and handles error correction from the physical later. they’re split up into sublayers called MAC or Logical Link Control (LLC) considered the most complex layers
data link
the ____ layer represents the electrical and physical representation of the system. This includes cable type, radio frequency, voltages, etc.
physical
what is one way to remember the OSI model?
All People Seem To Need Data Processing
what are the two popular network models that are based on the concept of layering?
OSI & TCP/IP model
_____ divides tasks into sub-tasks and then solve each sub-task independently. This establishes a well defined interface between the layers, making porting easier.
layering
what are the 2 advantages to layering?
code reuse, extensibility
what is a real world example of layering?
There’s a letter in an envelope with an address on the outside. the Fed ex man adds addressing information and barcode. the local office then delivers it to the hub where it’s sent via airplane to the nearest city. it’s then delivered to the right post office then the person
what are the upper layers of the OSI model that are called the Application Layers?
Application, Presentation, Session
what are the lower layers of the OSI model that are called the Data-Flow Layers?
Transport, Network, Data Link, Physical
each layer needs to add some ___ information to the data in order to do it’s jov
control
a ____ address is used to send messages from one host to all other hosts on a network
broadcasts
a ____ is an agreed upon convention for communication.
protocol
____ protocols describe the communication between layers on the same endpoint
interface
___-to-____ protocols describe communication between peers at the same layer
peer
which layers of the TCP/IP model contain protocols ?
application and transport layers
which layers of the TCP/IP model contain networks ?
Internet & network access layers
which model combines presentation and session layers into its application layer?
TCP/IP
which model combines the OSI data link and physical layers into on e layer?
TCP/IP
which model appears to be simpler because of its fewer layers?
TCP/IP
which model’s transport layer uses UDP but doesn’t always guarantee reliable delivery of packets
TCP/IP
a ____ is an executable file
program
a ____ or ____ is an instance of a program that’s being executed
process, task
a ____ ___ can generate multiple processes
single program
a ____ is a process, not a machine. it wait for a request from a client
server
a ___ is a process that sends a request to an existing server and waits for a reply
client
what are the 2 types of servers?
Iterative, Concurrent
____ servers handle many clients at a time
concurrent
____ servers handle one client at a time
iterative
TCP/IP uses an abstract destination point called a _____port
protocol
____ is a method of bundling data and methods that work within one unit.
encapsulation
which layer is responsible for encapsulation?
physical layer
